THE EARLY ABBAS1D PERIOD 67 Incidents made familiar to English readers in Moore's well-known poem. Its hero, Mokanna, known as Hakim Burkai, or " the Physician with the face-veil/' was born at Karez, which is now a squalid village on the road between Meshed and Herat. He taught the immanence of the Deity in Adam, in Abu Muslim, whose name was still Intensely revered, and in himself.1 For four years he held Central Asia, until, being besieged and seeing no hope, he cast himself into a tank of vitriol. Hadi, A.H. 169-170 (785-786).—Mehdi's favourite son was Haroun, who had gained much glory in a campaign to the Bosphorus In A.H. 156, and he wished to pass over his elder son Musa, better known as Had! ; but the latter refused to renounce his rights, and on the sudden death of Mansur he was proclaimed Caliph without opposition. His reign, however, was short and un- important, and when he died, after ruling for about a year, he was succeeded by his brother, who has achieved enduring fame as Haroun-al-Rashid, or " Aaron the Upright." Under him the golden age of Islam was ushered in. 1 Browne points out the essential identity of all these sects and gives details in vol. i. chap, ix, of his work.